The present invention relates to an ink jet printer and an ink container used therein for reserving ink.
An ink jet printer has an ink container for reserving ink that is to be supplied to a printing head. FIG. 1 shows a conventional ink container 200 disclosed in Japanese Laid-Open Patent Application No. HEI 6-183023. The ink container 200 includes a cartridge case 220 and a flexible pack 210 accommodated in the cartridge case 220. The ink container 200 is connected to a printing head (not shown) via a connecting pipe 208. Since the ink container 200 is replaceable, it is necessary to prevent ink leakage out of the ink container 200 particularly when the ink container 200 is being mounted on the ink jet printer. For this purpose, a pair of plate members 201 and 202 are provided in the interior of the flexible pack 210. Further, a compression spring 205 is provided between the plate members 201 and 202, which biases the plate members 201 and 202 away from each other. Due to the spring force of the compression spring 205, the capacity of the flexible pack 210 is increased, thereby to causes a negative pressure (that is, a pressure lower than air pressure) in the flexible pack 210. Thus, the ink leakage out of the ink container 200 is prevented.
However, since the compression spring 205 and the plate members 201 and 202 are provided in the flexible pack 210, the structure of the conventional ink container 200 is complicated. Particularly, it is difficult to manufacture the flexible pack 210 accommodating the compression spring 205 and the plate members 201 and 202 by mass-production process. Additionally, it is difficult to reduce the manufacturing cost of the ink container.